How can we use RS-485 in full-duplex ?

[ranran]

Hello,

We need to use RS-485 in full duplex, and with the flow control (DE).

Is it that when we configure DE with RS485 is shall be used as half duplex ?

can I configure rs232 pins with RTS (instead of DE) before converting voltage to rs-485 levels ?

Will this create a full duplex connection ? (CTS shall always be active in order to provide full duplex connection)

Thank you,

ran

[Tesla DeLorean]

>>We need to use RS-485 in full duplex...

That might prove quite challenging given the nature of the connection. Perhaps you're thinking of RS-422?

[ranran]

The HW engineer says it is a matter of voltage levels for the rs485.

He says that the devices in the end are capable of full duplex.

[ranran]

Hi,

Our HW engineer need the voltage levels of rs485.

Maybe we can configure the USART to use only RTS (instead of DE).

As I see flow control options are capable to use both RTS_CTS or only one of them (RTS or CTS alone) .

With this configuration I assume that the controller will remain in full duplex, Right ?

Thank you,

ran

[Tesla DeLorean]

Do you actually need hardware flow control in your application?

Look up diagrams of an RS-422 interface, ie where each signal is passed as a differential pair.​

[ranran]

Yes, This is a system requirement. We need flow control (but only for RTS pin).

[Tesla DeLorean]

So three differential pairs need to be run​

[ranran]

So, to work as full duplex, is it best to configure as rs232 (not rs485) with RTS ?

[Tesla DeLorean]

Depends on the application, you've indicated a desire to use differential drivers, to both transmit and receive simultaneously you will need at least two pairs.

Perhaps Google some images of RS-232, RS-485 and RS-422 interfaces so you have some conception about what's being discussed. ​

[ranran]

Do you mean pair of wires or of interfaces (ports) ?